Oil or other contaminants that spill or leak onto waterways or open bodies of water pose well-known ecological and economic problems. Expeditiously and economically cleaning up these contaminants can mitigate or avoid some of these problems.
Prior art systems for skimming oil and other lighter-than-water contaminants include disc oil skimmers, in which a rotating vertically oriented disc is partially submerged in a contaminated liquid, and contaminant that adheres to the rotating disc is wiped off by a doctor blade and collected in a container. The same principle is applied in drum or barrel style oil skimmers. Rope type oil skimmers cycle a loop of absorbent rope over the surface of the contaminated water and wring the contaminant out of the rope into a container. Variations on the rope type oil skimmer use plastic tubing or hose instead of rope and wipe the contaminant from the surface of the cycling tubing or hose. Weir type oil skimmers provide a sump and a weir (dam) that permits only the top layer of liquid (presumably the contaminant) to flow over the weir and be collected in the sump.
Porous bags have also been described for collecting floating contaminants. For example, U.S. Pat. No. 4,551,244 to Junichi Inoue discloses a two-hulled catamaran with a gun at the bow to sprays a gelling agent onto floating oil in front of the catamaran. A cage, disposed between the two hulls, houses a porous collection bag whose open side is directed toward the bow to collect gelled oil.
Prior art oil skimmer apparatus is, however, inadequate, particularly in situations where a vessel containing a skimmer needs to maneuver in an out of locations, such as coves.